Disposable absorbent articles have numerous applications including diapers, training pants, feminine care products, and adult incontinence products. A typical disposable absorbent article is formed as a composite structure including an absorbent assembly disposed between a liquid permeable bodyside liner and a liquid impermeable outer cover. These components can be combined with other materials and features such as elastic materials and containment structures to form a product which is specifically suited to its intended purposes.
For example, one such absorbent article is an infant's diaper, which typically includes components that are metered into the product in measured quantities. In particular, one such component generally included in an infant's diaper is SAM. Moreover, there is typically a target weight of the SAM in such articles. Achieving this target weight depends, in part, on the SAM dispense rate during a article manufacturing process. It has been discovered that the SAM dispense rate at machine start-up, and for some initial period thereafter, is often insufficient to achieve the target weight. Thus, a system is required for increasing the dispense rate of the SAM within this initial start-up period to reduce the number of articles produced containing insufficient amounts of SAM, and for maintaining the dispense rate at a level thereafter that reduces SAM waste.
Prior methods of controlling SAM specify the use of particulate regulating means such as a feed screw device which relies on gravitational forces to regulate the flow of particulate material such as SAM. Other methods include controlling the feed screw to yield an amount of particulate material to match a setting during a steady state operation. However, existing methods do not disclose controlling the feed screw to insure a proper amount of particulate material is dispensed during transient events such as machine startups.
In spite of past efforts, there is a need for improved methods and systems for controlling dispense rates of SAM during a manufacturing process.
The invention described below addresses one or more of these and other disadvantages and needs.